The invention relates generally to x-ray imaging and, more particularly, to reduced access x-ray imaging.
The early detection of corrosion and cracks is particularly important in the airline industry in order to remove and repair unsatisfactory or damaged components to prevent potentially harmful part failure. Because flaws often develop below the surface and spread to the surface of a component, detection of sub-surface flaws such as cracks and corrosion is necessary for early identification of an unsatisfactory airplane component, such as a wing or fuselage . Flaws also arise in hidden areas and in areas that are difficult to access on an aircraft, and these flaws must also be detected.
X-ray imaging provides a useful tool for detecting both sub-surface flaws and flaws that are hidden beneath other structure. X-ray imaging is well known and will not be described in detail. Briefly, a test object is exposed to a beam of x-ray radiation. The x-ray radiation is modulated by passage through the test object because x-ray absorption rates for cracks and other flaws differ from that of undamaged portions of the test object. The resulting x-ray flux is detected by an x-ray detector, which converts the flux information to electrical signals. The electrical signals are then processed for analysis or display.
Currently, x-ray imaging is used to inspect airplane components repeatedly throughout a component""s life-span. Essentially, a plane is periodically taken out of service, its interior is removed, and the critical components, such as the wings, are disassembled. A target component, e.g. a wing or a horizontal stablizer, is then imaged, for example by covering the wing or horizontal stabilizer with an x-ray sensitive material and placing a powerful x-ray source within the wing. Although this x-ray inspection technique provides useful images of the airplane components, it has a number of drawbacks, including the large amount of time required to disassemble and reassemble an airplane and the associated cost. In addition, the disassembly and the reattachment of the wings and the fuselage introduce additional inspection steps. Namely, the interface between a reassembled wing and fuselage must be inspected. For example, the rivets must be probed. The additional inspection steps further increase the inspection cost and time.
Accordingly, it would be desirable to develop an x-ray imaging apparatus for inspecting remote portions of a test object, such as an airplane component. Additionally, it would be desirable if the apparatus could be manipulated and controlled from a position remote to the portion of the test object under examination. Similarly, it would be desirable for the apparatus to permit collection of x-ray image data at the remote position. Furthermore, it would be desirable if the apparatus could be maneuvered through narrow areas for inspecting reduced access portions of a test object to obviate disassembly of the test object. Such an apparatus would reduce inspection time and cost and, in addition, would eliminate the additional problems currently introduced by disassembling and reattaching components, such as airplane wings and fuselage.
Briefly, in accordance with one embodiment of the present invention, an x-ray imaging device includes a borescope and an x-ray detector positioned at a distal end of the borescope. Advantageously, the x-ray imaging device can be used to image remote portions of a test object.